(noun) - a sexual act involving a clown, a chimpanzee skeleton, an apple pie, a wheelchair, a bowling pin, a bible, exactly three tubes of toothpaste, a compass, a grandfather clock, a barbie doll, a carton of egg nog, and a cattle prod.

The best-kept secret in the sexual world. When a man sprinkles taco seasoning on his dong and fucks her up the ass so fast that the girl's anus begins to smoke, he can say he gave her a mexican smokestack. The friction generated with the taco seasoning causes the burning to actually smell like mexican food. I love it.

"...that was disgusting!"
"Not as disgusting as Michael giving Maggie a mexican smokestack."